Git commits in Moodle 3.7.1 by Didier 'OdyX' Raboud

commit cd9c54c93c2c37ce6986f1274e3a0bf3700fbee0
Author: Didier 'OdyX' Raboud <didier.raboud@liip.ch>
Date:   Thu, 14 Mar 2019 21:00:27 +0800
Tag:    v3.7.1

MDL-65067 analytics: Strengthen format_weeks detection